Towards a better understanding of commonly used medicinal plants from Turkiye: Detailed phytochemical screening and biological activity studies of two Teucrium L. species with in vitro and in silico approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Since ancient times, Teucrium L. species have been among the most commonly used traditional medicinal plants mainly in the Mediterranean region. From tackling gastrointestinal problems to maintaining the healthy functioning of endocrine glands, and from treating malaria to severe dermatological disorders, Teucrium species are known to have extensive therapeutic applications. Teucrium polium L. and Teucrium parviflorum Schreb. are the two members of the genus that have been used in Turkish folk medicine for various medicinal purposes. AIM OF THE STUDY: To determine the phytochemical compositions of the essential oils and ethanol extracts of Teucrium polium and Teucrium parviflorum collected from different locations in Turkiye along with the investigation of in vitro antioxidant, anticancer, antimicrobial activities, and both in vitro and in silico enzyme inhibitory activities of the extracts. MATERIALS AND METHODS: Ethanol extracts of Teucrium polium aerial parts and roots, and aerial parts of Teucrium parviflorum were prepared. Volatile profiling of the essential oils by GC-MS, phytochemical profiling of the ethanol extracts by LC-HRMS, antioxidant activity by DPPH radical scavenging, ABTS cation radical scavenging, CUPRAC, and metal chelating activity assays, anticholinesterase, antityrosinase, antiurease, activities by different enzyme inhibitory activity assays, anticancer activity by SRB cell viability assay, and antimicrobial activity against a standard panel of bacteria and fungi by the microbroth dilution technique. Molecular docking studies were performed by Autodock Vina (Ver. 1.1.2). RESULTS: The studied extracts were found to be quite rich in various biologically important volatile and phenolic compounds. (-)-Epigallocatechin gallate, which is a molecule renowned for having great therapeutic potential, was the major compound of all extracts. Teucrium polium aerial parts extract was revealed as a great source for naringenin with 16327 ± 685.23 µg/g extract. All extracts exerted significant antioxidant activity by different methods. All extracts demonstrated antibutrylcholinesterase, antityrosinase, and antiurease activities by in vitro and in silico assays. Teucrium polium roots extract stood out with remarkable tyrosinase and urease inhibitory and cytotoxic activities. CONCLUSION: The obtained results from this multi-disciplinary study proves that the traditional use of these two Teucrium species is justified, and the mechanisms behind are enlightened.

The Therapeutic Potential of Ethnomedicinally Important Anatolian Thyme Species: A Phytochemical and Biological Assessment.

Thyme has been used for various therapeutic purposes in many different cultures, which makes it one of the most riveting medicinal plants throughout history. From its beneficial effects on the respiratory tract or the gastrointestinal system, to its unique skin-related activities, the investigation of the medicinal properties of thyme has always been an alluring topic for researchers aiming to develop conventional medications from this traditional herb. With an incentive to contribute to the extensive thyme research, three Thymus L. species namely Thymus cariensis Hub-Mor. & Jalas (endemic), Thymus praceox subsp. grossheimii (Ronniger) Jalas, and Thymus pubescens Boiss. et Kotschy ex Celak from Turkey were deeply investigated within this study. The analysis of the phytochemical constituents of the extracts was conducted by LC-MS/MS. 12 biologically important secondary metabolites (p-coumaric acid, caffeic acid, salicylic acid, quinic acid, fumaric acid, vanillin, malic acid, rutin, apigenin, naringenin, and nicotiflorin) were detected in all extracts. Their total phenolic and flavonoid contents were calculated (11.15 ± 0.17-61.12 ± 2.59 µg PEs/mg extract, 2.53 ± 0.04-40.28 ± 0.92 µg QEs/mg extract, respectively), and the antioxidant potential of the extracts was evaluated by DPPH and ABTS radical scavenging and CUPRAC activity methods, accordingly, the extracts were shown to possess significant antioxidant activity. Among them, Thymus cariensis Hub-Mor. & Jalas was the most active with IC50 values of 34.97 ± 1.00 µg/ml and 9.98 ± 0.04 µg/ml regarding the DPPH and ABTS radical scavenging assays, respectively, and an A0.5 value of 5.80 ± 0.02 µg/ml according to CUPRAC activity method. Their anticholinesterase, antityrosinase, and antiurease activities were also tested, Thymus cariensis Hub-Mor. & Jalas (35.61 ± 1.20%) and Thymus pubescens Boiss. et Kotschy ex Celak aerial part extract (33.49 ± 1.39%) exhibited moderate antibutyrylcholinesterase activity at 200 µg/ml concentration. The results of the cell viability assay indicated that the extracts demonstrated moderate-to-low cytotoxicity on A498 human renal cell lines. Furthermore, all studied extracts exerted noteworthy antimicrobial activity, especially against Candida tropicalis (MIC values: 19.53-78.12 µg/ml). The presented data substantiates the use of thyme extracts as therapeutic agents in both ethnomedicine and conventional therapies.

Terpenoid and Fatty Acid Profiling along with Anti-Tyrosinase and Anti-Urease Potentials of Scorzonera pygmaea Sibth. & Sm. an Endemic Plant of Turkey.

Petroleum ether (PE), chloroform (CH), ethyl acetate (EA) and butanol (BU) fractions were obtained from ethanol extracts of the roots (SPR) and the above ground (SPH) parts of S. pygmaea. PE fractions were evaluated by GC/MS for profiling the terpenoids and the fatty acids of the plant. 29 compounds in total including saturated (major palmitic acid), unsaturated (major linoleic acid) fatty acids and triterpenes were tentatively determined. Short-term extraction methods might be preferred to avoid esterification of fatty acids. Phytochemical profiles of SPR-PE and SPH-PE were found to be similar to each other and to other few Scorzonera species reported previously. These results will contribute to the chemotaxonomic studies about the genus which is considered taxonomically complex genus. Activity studies were carried out using kojic acid (87.10 % inhibition) standard for tyrosinase and thiourea (95.83 % inhibition) standard for urease. SPR-CH was determined as the most potent fraction with 55.94 % and 55.10 % inhibition of tyrosinase and urease, respectively at the same concentration of the standards (200 microgram/mL). These moderate results might be considered encouraging for more detailed studies to determine the active compounds and to evaluate the plant's potential in pharmaceutical, food and cosmetic industries in terms of tyrosinase and urease inhibition.

Volatile and phenolic profiling of a traditional medicinal plant, Hypericum empetrifolium with in vitro biological activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Hypericum empetrifolium Willd is a member of the Hypericaceae family, mainly known in southern Greece, and western Turkey. Being a centuries-old medicinal plant, the aerial parts of the plant have been used for the treatment of herpes, kidney stones, gastric ulcer, and also for their anti-helminthic, and diuretic purposes traditionally. AIM OF THE STUDY: The current study aimed to investigate the phytochemical profiles of the essential oil, and two ethanol extracts prepared from the aerial parts (H. empetrifolium aerial parts extract - HEA), and roots of the plant (H. empetrifolium roots extract - HER), and to provide data on antioxidant, anticholinesterase, antityrosinase, antiurease, cytotoxic, and antimicrobial activities of the extracts. MATERIALS AND METHODS: In this study, volatile and phenolic compounds of the HEA and HER were analyzed by GC-MS and LC-MS/MS, respectively. Antioxidant potential of the extracts was clarified by using DPPH radical scavenging assay, ABTS cation radical assay, and the CUPRAC assay. Acetylcholinesterase, butyrylcholinesterase, urease, and tyrosinase inhibitory activity assays were used to determine enzyme inhibition capacity of the extracts. Cytotoxic activity of the extracts was established by using XTT assay. The antimicrobial activity of the extracts was determined by the microbroth dilution technique. RESULTS: The major compounds of the essential oil were revealed as alloaromodendrene (24.7%), α-pinene (14.7%), ß-pinene (10.7%), and α-terpineol (7.7%) by the GC-MS analysis. According to the LC-MS/MS analysis results, quinic acid was the most abundant constituent in both extracts with 20612.42 ± 169.02 µg/g extract in HEA extract, and with 2254.34 ± 18.49 µg/g extract in HER extract, respectively. The HEA extract was also found to be rich in terms of chlorogenic acid (5583.14 ± 38.52 µg/g extract), isoquercitrin (3076.77 ± 40.92 µg/g extract), and malic acid (2822.90 ± 31.90 µg/g extract). HEA extract exhibited a significant antioxidant effect with an IC50 value of 11.98 ± 0.22 µg/mL according to the DPPH radical scavenging assay. Similar results were obtained with the ABTS cation radical assay, and the CUPRAC assay. HER extract showed a strong butyrylcholinesterase inhibitory effect with 88.69 ± 0.62% at 200 µg/mL concentration. Both extracts were considered to have moderate anti-tyrosinase activity compared to the standard at 200 µg/mL. The best antimicrobial activity was obtained for HEA against C. parapsilosis with an MIC value of 4.88 µg/mL. HEA also exhibited antifungal activity against C. tropicalis with 19.53 µg/mL. Only HER exhibited low cytotoxicity on A498 renal cell lines with 60.6% cell viability. CONCLUSION: Unquestionably, H. empetrifolium Willd has ethnopharmacological importance according to these results, and further investigations are required to evaluate other therapeutic properties of the plant.

Anticholinesterase and Antioxidant Activities of Natural Abietane Diterpenoids with Molecular Docking Studies.

BACKGROUND: Alzheimer's Disease (AD) is one of the most prevalent causes of dementia in the world, and no drugs available that can provide a complete cure. Cholinergic neurons of the cerebral cortex of AD patients are lost due to increased activity of cholinesterase enzymes. OBJECTIVE: Acetylcholinesterase (AChE) and Butyrylcholinesterase (BuChE) are the two major classes of cholinesterases in the mammalian brain. The involvement of oxidative stress in the progression of AD is known. Thus, the objective of this study is to determine strong ChE inhibitors with anti-oxidant activity. METHODS: In this study, 41 abietane diterpenoids have been assayed for antioxidant and anticholinesterase (both for AChE and BuChE) properties in vitro, which were previously isolated from Salvia species, and structurally determined by spectroscopic methods, particularly intensive 1D- and 2DNMR and mass experiments. Molecular modeling studies were performed to rationalize the in vitro ChE inhibitory activity of several abietane diterpenoids compared with galantamine. RESULTS: Thirteen out of the tested 41 abietane diterpenoids exhibited at least 50% inhibition on either AChE or BuChE. The strongest inhibitory activity was obtained for Bractealine against BuChE (3.43 µM) and AChE (33.21 µM) while the most selective ligand was found to be Hypargenin E against BuChE enzyme (6.93 µM). A full correlation was not found between anticholinesterase and antioxidant activities. The results obtained from molecular modelling studies of Hypargenin E and Bractealine on AChE and BuChE were found to be in accordance with the in vitro anti-cholinesterase activity tests. CONCLUSION: Abietane diterpenoids are promising molecules for the treatment of mild-moderate AD.

Comprehensive analysis of an uninvestigated wild edible medicinal garlic species from Turkey: Allium macrochaetum Boiss. & Hausskn.

The study was aimed to investigate the phenolic compounds of Allium macrochaetum by LC-MS/MS, as well as the antioxidant, antialzheimer, and antimicrobial activities of the extracts, and determination of the essential oil and fatty acid compositions by GC-MS. The results indicate that malic acid and t-caffeic acid are the major compounds in the bulbs. The main components of fatty acids were found to be linolenic (40.72%), oleic (19.79%), and palmitic (18.45%) acids. The allyl disulfide (66.97%) was found as major compound in the essential oil. The ethanol extract of the bulbs exhibited stronger ABTS cation (IC50 : 55.90 ± 1.08 µg/ml) and DPPH free (IC50 : 204.43 ± 2.17 µg/ml) radical scavenging activities than the other extracts. The extract also showed moderate cupric reducing activity with 1.52 absorbance at 100 µg/ml concentration. Only the ethanol extract of the bulbs showed weak inhibition (23.34 ± 0.11%) against butrylcholinesterase enzyme at 200 µg/ml. PRACTICAL APPLICATIONS: Allium macrochaetum is a wild and edible garlic species which grown in Turkey, Iran, Iraqi, and Syria. A. macrochaetum has been used by local people in Turkish folk medicine as an antibiotic, and for the treatment of alopecia. The health benefits and nutritional values of A. macrochaetum were clarified in the first time. Phenolic compounds of A. macrochaetum were detected by LC-MS/MS. The essential oil and fatty acid compositions of A. macrochaetum were identified by GC-MS. Antioxidant, antialzheimer, and antimicrobial activities potential of A. macrochaetum were determined.

A comprehensive LC-MS/MS method validation for the quantitative investigation of 37 fingerprint phytochemicals in Achillea species: A detailed examination of A. coarctata and A. monocephala.

The current study aims to optimize and validate a comprehensive LC-MS/MS method for the quantification of 37 phytochemicals (15 phenolic acids, 17 flavonoids, 3 non-phenolic organic acids, 1 phenolic aldehyde and 1 benzopyrene) in Achillea species. Though Achillea species were chosen as real life samples, the current method is applicable to a wide range of plant species. The developed method was fully validated in terms of linearity, accuracy (recovery), inter-day and intra-day precision (repeatability), limits of detection and quantification (LOD/LOQ) and relative standard uncertainty (U% at 95% confidence level (k = 2)). Reversed-phase ultrahigh performance liquid chromatography was optimized to achive optimum separation for 37 phytochemical compounds and to overcome the suppression effects. MS detection was performed using a triple quadrupole mass spectrometer and negative or positive ionization modes were optimized for each analyte. Multiple reaction monitoring (MRM) was used to quantify the analytes, related molecular ions and transition ions were optimized. Phytochemical screening of ethanol and methanol-chloroform extracts of root and aerial parts of A. coarctata and A. monocephala were performed by using the developed and validated LC-MS/MS method. Root and aerial parts of both species have considerable amounts of certain phenolic-nonphenolic acids (quinic, malic, fumaric, chlorogenic and vanillic acids) and flavonoids (rutin, hesperidin, isoquercitrin, apigetrin, luteolin, apigenin). Additionally, total phenolic and flavonoid amounts, antioxidant (DPPH free radical scavenging assay, ABTS radical cation decolorization assay, ß-carotene lipid peroxidation test system and CUPRAC cupper reduction capacity methods), anticholinesterase, tyrosinase, urease inhibition and cytotoxic activities (on HeLa (Human Cervical Carcinoma Cell Line) of A. coarctata and A. monocephala were also investigated. It has been determined that the studied Achillea species, that are rich in total phenolic-flavonoid and chlorogenic acid contents, have high antioxidant and cytotoxic potential at the same time. According to the results of LC-MS/MS, antioxidant and cytotoxic activity studies, after detailed chemical investigation and toxicity studies on these species, A. coarctata and A. monocephala may be promoted as promising sources of natural agents and used for the development of nutraceuticals or functional food ingredients in future.

Chemical profile and biological activities of Veronica thymoides subsp. pseudocinerea.

CONTEXT: In Turkey, Veronica species (Plantaginaceae) have been used as a diuretic and for wound healing in traditional medicine. OBJECTIVE: To examine the fatty acid and essential oil profiles, the antioxidant, anticholinesterase, antimicrobial, and DNA damage effects of Veronica thymoides P.H. Davis subsp. pseudocinerea M.A. Fischer as a potential source of natural active compounds. MATERIALS AND METHODS: GC/MS was used to analyze essential oil and fatty acid obtained from whole plant. The antioxidant activity was evaluated by the ß-carotene-linoleic acid test system, DPPH-free and ABTS cation radicals scavenging, and cupric reducing antioxidant capacity assays. The anticholinesterase and antimicrobial activities were determined by Ellman and broth macrodillution methods, respectively. The effect of the methanol extract on DNA cleavage was investigated. RESULTS: Hexatriacontene (21.0%) was found to be the main constituent in essential oil, and linoleic acid (25.2%) and palmitic acid (20.6%) in fatty acid. Methanol extract demonstrated the best IC50 values in lipid peroxidation (49.81 ± 0.31 µg/ml) and DPPH-free radical scavenging activity (15.32 ± 0.17 µg/ml). Methanol and water extracts possessed strong ABTS cation radical scavenging activity with IC50 values 9.15 ± 0.28 and 8.90 ± 0.1 µg/ml, respectively. The acetone extract exhibited moderate butyrylcholinesterase inhibitory activity. The highest antimicrobial activity was determined in methanol extract against Escherichia coli with 31.25 µg/ml MIC value. Inhibition of methanol extract on plasmid DNA cleavage by OH radicals was found to be 93.32% at 500 µg/ml. CONCLUSION: The methanol extract having strong antioxidant and DNA damage effects could be investigated phytochemically to find natural active compounds.

Essential oil compositions and anticholinesterase activities of two edible plants Tragopogon latifolius var. angustifolius and Lycopsis orientalis.

This is the first report in the literature on essential oil compositions of Tragopogon latifolius var. angustifolius and Lycopsis orientalis which were analysed by using GC-FID and GC-MS techniques. The main constituents of T. latifolius var. angustifolius were identified as α-selinene (10.5%), 2,5-di-tert octyl-p-benzoquinone (9.5%) and valencene (7.0%); however, the main components of L. orientalis were identified as heptacosane (10.5%), τ-muurolene (9.6%) and tetratetracontane (9.4%). The essential oils of T. latifolius var. angustifolius and L. orientalis species exhibited moderate inhibitory activity against acetyl- and butyryl-cholinesterase enzymes at 200 µg/mL.

Chemical compositions by using LC-MS/MS and GC-MS and biological activities of Sedum sediforme (Jacq.) Pau.

In this research, the chemical composition and biological activities of various extracts obtained from whole parts of Sedum sediforme (Jacq.) Pau were compared. The amounts of total phenolic and flavonoid components in crude extracts were determined by expression as pyrocatechol and quercetin equivalents, respectively. All of the extracts (petroleum ether, acetone, methanol, and water) obtained from S. sediforme showed strong antioxidant activity in four tested methods. Particularly, the IC50 values of the methanol extract, which was the richest in terms of total phenolic and flavonoid contents, were found to be lower than those of α-tocopherol and BHT in ß-carotene bleaching (9.78 ± 0.06 µg/mL), DPPH free radical scavenging (9.07 ± 0.07 µg/mL), and ABTS cation radical scavenging (5.87 ± 0.03 µg/mL) methods. Furthermore, the methanol extract of S. sediforme showed higher inhibition activity than galanthamine against acetyl- and butyryl-cholinesterase enzymes. Also, acetone and methanol extracts exhibited moderate antimicrobial activity against Candida albicans. The main constituents of fatty acid and essential oil were identified as palmitic acid (C16:0) (28.8%) and α-selinene (20.4%), respectively, by GC-MS. In the methanol extract of S. sediforme, quercetin, rutin, naringenin, and protocatechuic, p-coumaric, caffeic, and chlorogenic acids were detected and quantified by LC-MS/MS. Results of the current study showed that the methanol extract of S. sediforme may also be used as a food supplement.

Chemical constituents and biological activities of Cirsium leucopsis, C. sipyleum, and C. eriophorum.

Two endemic Cirsium species, C. leucopsis DC. and C. sipyleum O. Schwarz, and C. eriophorum (L.) Scop. growing in Turkey were investigated to establish their secondary metabolites, fatty acid compositions, and antioxidant and anticholinesterase potentials. Spectroscopic methods were used to elucidate the structures of thirteen known compounds (p-hydroxy-benzoic acid, vanillic acid, cis-epoxyconiferyl alcohol, syringin, balanophonin, 1'-O-methyl-balanophonin, apigenin, kaempferol-3- O-ß-D-glucopyranoside, kaempferol-3-O-α-L-rhamnopyranoside, taraxasterol, taraxasterol acetate, ß-sitosterol, ß-sitosterol-3-O-ß-D-glucopyranoside). cis-Epoxyconiferyl alcohol and 1'-O-methyl- balanophonin were isolated for the first time from Cirsium species. Palmitic acid (47.1%) was found to be the main fatty acid of C. leucopsis, linoleic acid in both C. sipyleum (42.1%) and C. eriophorum (37.8 %). Assays of ß-carotene bleaching, scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS) cation radicals, and superoxide anion radicals, as well as cupric reducing antioxidant capacity (CUPRAC) were used to determine the antioxidant activities of the extracts and isolated compounds. Vanillic acid, balanohonin, and kaempferol-3-O-aαL-rhamnopyranoside exhibited strong antioxidant activity. Taraxa-terol was a potent inhibitor of acetyl- and butyrylcholinesterase activity, respectively.

Indole alkaloids from Vinca major and V. minor growing in Turkey.

A new indole alkaloid, 11-hydroxypolyneuridine, was isolated from Vinca major subsp. major L. and the known indole alkaloids vallesiachotamine and isovallesiachotamine from Vinca minor L. This is the first report on the alkaloids of both Vinca species growing in Turkey; vallesiachotamine and isovallesiachotamine were isolated from a Vinca species for the first time. V. minor may be considered as a new source for these two alkaloids due to their occurrence in high amount in the aerial parts of the plant. The alkaloid extracts of the two Vinca species were found to have high lipid peroxidation inhibitory and DPPH radical scavenging activities. Anticholinesterase activity of the extracts was also very strong.

Antioxidant and anticholinesterase activities of eleven edible plants.

CONTEXT: Consumers have become more interested in beneficial effects of vegetables, fruits, and tea to protect their health. OBJECTIVE: The antioxidant potential and anticholinesterase activity of eleven edible plants were investigated. MATERIAL AND METHODS: The dichloromethane, ethanol and water extracts prepared from celery [Apium graveolens L. (Umbelliferae)], Jerusalem artichoke [Helianthus tuberosus L. (Compositae)], spinach [Spinacia oleracea L. (Chenopodiaceae)], chard [Beta vulgaris L. var. cicla (Chenopodiaceae)], purslane [Portulaca oleracea L. (Portulacaceae)], ispit, or borage [Trachystemon orientale (L.) G. Don (Boraginaceae)], garden rocket [Eruca sativa Mill. (Brassicaceae)], red cabbage [Brassica oleracea L. var. capitata f. rubra DC. (Cruciferae)], lime flower [Tilia tomentosa Moench (Tiliaceae)], cinnamon [Cinnamomum cassia Presl. (Lauraceae)], and rosehip [Rosa canina L. (Rosaceae)], were tested to determine their antioxidant and anticholinesterase activities by using CUPRAC (cupric reducing antioxidant capacity) and Ellman methods, respectively, for the first time. RESULTS: As a result, the dichloromethane, ethanol and water extracts of cinnamon showed the best antioxidant effect among the extracts of the tested plants. The ethanol extract of cinnamon exhibited 63.02% inhibition against acetylcholinesterase and 85.11% inhibition against butyrylcholinesterase (BChE) at 200 µg/mL concentration while the dichloromethane extract of garden rocket possessed the highest inhibition (91.27%) against BChE among all the tested extracts. DISCUSSION AND CONCLUSION: This study indicated that the ethanol extract of cinnamon may be a new potential resource of natural antioxidant and anticholinesterase compounds.

Antioxidant and anticholinesterase activity evaluation of ent-kaurane diterpenoids from Sideritis arguta.

The petroleum ether and acetone extracts of the aerial parts of Sideritis arguta afforded two new and six known diterpenoids with the ent-kaurane skeleton. The structures of the new diterpenoids were determined as ent-7alpha,18-diacetoxy-16beta-hydroxykaurane (diacetyldistanol) (1) and ent-7alpha-acetoxy,15alpha,18-dihydroxykaur-16-ene (15-epi-eubol) (2) by spectroscopic data interpretation. Antioxidant potential was investigated for the ent-kauranes and the plant extracts by three methods (beta-carotene bleaching, free-radical scavenging, and superoxide-anion scavenging activity). Acetylcholinesterase and butyrylcholinesterase inhibitory activity were also evaluated, and the ent-kauranes eubol (3), sideroxol (5), and 7-epi-candicandiol (6) exhibited moderate butyrylcholinesterase inhibitory activity.